'the nature of your complaint' is correct and can be used in written English. For example, you could use it in an email to a customer service team: "Please could you provide me with an update on the nature of your complaint?".
The nature of your complaint in no more than 500 words.
Question 3: Choose the option that you believe best describes the nature of your complaint.
Some LAs list the departments to approach according to the nature of your complaint, others operate a "one-stop shop" which will deal with all complaints.
Local authorities and health authorities are currently responsible for residential or nursing homes - who you should complain to depends on the nature of your complaint.
The menus, for instance, help you explain the nature of your complaint — late fees, billing disputes, interest rate, etc. — and what, if anything, you've done so far to resolve it.
So what, exactly, is the nature of your complaint?
Determine the nature of a legitimate complaint about your service provider.
Maybe I don't understand the nature of the complaint.
The Government lawyers would not elaborate on the nature of the complaint.
Uncertain of the cause or even the nature of the complaint, Pouch sent the man to the emergency room.
On Tuesday, Gregg Adler, Mr. Plofsky's lawyer, said his client had not been told the nature of the complaint.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK